// G5BGRA Coursework // 240x240 pixel JPEG chroma keying program // @author Anthony Jaroslav Truhlar // 28/12/1998 // Email: ajt97c@cs.nott.ac.uk /* Extra features: =============== 1. Ability to set values of the hue of chroma keying colour and the +/- deviation by typing them into the text boxes (return must be pressed) as well as by adjusting the scrollbars. 2. Canvas update methods overrided to only clear when necessary - this prevents 'flicker' when buttons are pressed and hence images redrawn. Note that the bounding rectangles are still drawn, and this has been left in to give some indication to the user that the given image is being drawn. 3. Size of main frame set to 732x400 since the layout method used only gave canvasses of 237x240 (measured with Paint Shop Pro); when the main frame size was set at 720x400. The adjustment allows the required size of canvas (240x240) to be displayed. */ // Import required classes import java.awt.*; // AWT's components import java.awt.event.*; // AWT's event handling class import java.awt.image.*; // AWT's image manipulaton/processing class // Use innner classes public class ajt97c extends Frame { // declare constants for frame size int mainWidth = 732; // to ensure 240x240 panels int mainHeight = 400; // (720x400 only gives 237x240 panels with layout used) public static void main(String args[]) { // create frame for application new ajt97c(); } // end of main ajt97c() { // constructor for ajt97c // set title of main frame setTitle("Anthony Jaroslav Truhlar, ajt97c*"); // set size of main frame setSize(mainWidth,mainHeight); // center frame (if display big enough) Toolkit tk = Toolkit.getDefaultToolkit(); Dimension d = tk.getScreenSize(); int screenHeight = d.height; int screenWidth = d.width; if ( screenWidth <= mainWidth ) { // deal with non-SVGA displays setLocation(0,((screenHeight-mainHeight)/2)); } else { setLocation(((screenWidth-mainWidth)/2),((screenHeight-mainHeight)/2)); } // end if setResizable(false); // ensure frame isn't resized [jdk 1.1.7 or better] // add listener for window events addWindowListener ( // pass an instance of WindowAdapter to save // re-writing the 7 required methods new WindowAdapter() { // override windowClosing() method to exit on window close public void windowClosing(WindowEvent e) { System.exit(0); // terminate } // end of windowClosing } // end of instance of WindowAdapter ); // end of WindowListener declaration // add a panel add(new mainPanel()); show(); } // end of constructor for ajt97c public class mainPanel extends Panel { // declare variables for use in mainPanel // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ // declare a panel for each image, and one for the buttons, etc Panel topMain = new Panel(new GridLayout(1,3)); // has next 3 panels Panel fgPanel = new Panel(); // panel for foreground image canvas Panel keyedPanel = new Panel(); // panel for keyed image canvas Panel bgPanel = new Panel(); // panel for background image canvas Panel uselessPanel = new Panel(); // this panel is for 'padding' only Panel bttmMain = new Panel(new GridLayout(2,4)); // contains widgets // delcare canvasses for the images Canvas fgCanvas = new fgndCanvas(); // canvas for foreground image Canvas keyedCanvas = new keyedCanvas(); // canvas for keyed image Canvas bgCanvas = new bkgndCanvas(); // canvas for background image // declare the images Image fgImage = Toolkit.getDefaultToolkit().getImage("fiona.jpg"); Image bgImage = Toolkit.getDefaultToolkit().getImage("back.jpg"); Image fgImage2, bgImage2, keyedImage; // images to be generated from memory // delcare integers for width & height of images int imgWidth = 240; int imgHeight = 240; // declare 1D arrays for pixels int[] fgPixels = new int [imgWidth*imgHeight]; int[] keyedPixels = new int [imgWidth*imgHeight]; int[] bgPixels = new int [imgWidth*imgHeight]; // declare pixel grabbers for the images PixelGrabber fgPg = new PixelGrabber(fgImage,0,0,imgWidth,imgHeight,fgPixels,0,imgWidth); PixelGrabber bgPg = new PixelGrabber(bgImage,0,0,imgWidth,imgHeight,bgPixels,0,imgWidth); // declare the four buttons for loading, clearing and keying images Button loadfg = new Button("LOAD FG"); Button clear = new Button("CLEAR"); Button key = new Button("KEY"); Button loadbg = new Button("LOAD BG"); // scrollbars for selecting the hue and +/- deviation of chroma key colour Scrollbar chromaHue = new Scrollbar(Scrollbar.HORIZONTAL,0,0,0,361); Scrollbar hueRange = new Scrollbar(Scrollbar.HORIZONTAL,0,0,0,181); // text fields to display the value of the selected hue TextField chromaVal = new TextField("0",3); // set field length to 3 chars TextField rangeVal = new TextField("0",3); // values of the scrollbars (initialise to zero) int chroma = 0, deviation = 0; // booleans to denote whether or not image is loaded or cleared boolean fgloaded = false, justloadedfg = false, bgloaded = false; boolean clearfg = false, clearkeyed = false, clearbg = false; boolean keyed = false; mainPanel() { // constructor for mainPanel setLayout(new BorderLayout()); // use border layout for main panels // add major panels to frame add("North", topMain); add("Center", uselessPanel); add("South", bttmMain); // add image panels to top panel topMain.add(fgPanel); topMain.add(keyedPanel); topMain.add(bgPanel); // set the size of the panels topMain.setSize(mainWidth,imgHeight); fgPanel.setSize(imgWidth,imgHeight); keyedPanel.setSize(imgWidth,imgHeight); bgPanel.setSize(imgWidth,imgHeight); uselessPanel.setSize(mainWidth,140); bttmMain.setSize(mainWidth,20); // set the size of the canvasses fgCanvas.setSize(imgWidth,imgHeight); keyedCanvas.setSize(imgWidth,imgHeight); bgCanvas.setSize(imgWidth,imgHeight); // add canvasses to appropriate panels fgPanel.add(fgCanvas); bgPanel.add(bgCanvas); keyedPanel.add(keyedCanvas); // add AWT widgets to bottom panel bttmMain.add(chromaVal);// text field to display hue of chroma key colour bttmMain.add(chromaHue);// scrollbar to select hue of chroma key colour bttmMain.add(hueRange); // scrollbar to select +/- devaition of hue bttmMain.add(rangeVal); // text field to display +/- deviation of hue bttmMain.add(loadfg); // button to load foreground image bttmMain.add(clear); // button to clear canvasses bttmMain.add(key); // button to activate chroma-keying bttmMain.add(loadbg); // button to load background image // add action listeners to send events from above widgets to mainPanel chromaVal.addActionListener(new chromaTFAListener()); chromaHue.addAdjustmentListener(new chromaADJListener()); hueRange.addAdjustmentListener(new rangeADJListener()); rangeVal.addActionListener(new rangeTFAListener()); loadfg.addActionListener(new loadfgBAListener()); clear.addActionListener(new clearBAListener()); key.addActionListener(new keyBAListener()); loadbg.addActionListener(new loadbgBAListener()); } // end of constructor for mainPanel // return maximum of three doubles public double getMax(double a, double b, double c) { double temp = Math.max(a,b); return Math.max(temp,c); } // end of getMax // return minimum value of three doubles public double getMin(double a, double b, double c) { double temp = Math.min(a,b); return Math.min(temp,c); } // end of getMin // return the hue of a pixel as an integer value public int getH(int pixel) { // delcare vars double hue = 0, sat = 0, value = 0, maximum = 0, minimum = 0, diff = 0; // split RGB value into seperate doubles (one for each colour) // int alpha = (pixel & 0xff000000)>>24; (ignore alpha) double red = (pixel & 0x00ff0000)>>16; double green = (pixel & 0x0000ff00)>>8; double blue = (pixel & 0x000000ff); // determine the largest value out of the colours maximum = getMax(red, green, blue); // determine the smallest value out of the colours minimum = getMin(red, green, blue); // set value value = maximum; // set saturation, which is zero if r,g,b are all 0 sat = (maximum != 0) ? ((maximum - minimum) / maximum):0; // when saturation is 0, hue is undefined if (sat == 0) { return 0; } // end if // determine difference between max & min diff = maximum - minimum; // calculate hue based on symmetry of hexagon (see RGB2HSV.PDF) if ( maximum == red ) { // colour between magenta and yellow hue = ((green - blue) / diff) * 60; } else { if ( maximum == green ) { // colour between yellow and cyan hue = (2 + ((blue - red) / diff)) * 60; } else { // colour between cyan and magenta hue = (4 + ((red - green) / diff)) * 60; } // end if } // end if if ( hue < 0 ) { hue += 360; // if hue is negative add 360 degrees } // end if return (int)hue; // return the hue of the pixel } // end of getH // ############## // DISPLAY IMAGES // ############## public class fgndCanvas extends Canvas { public void paint(Graphics g) { Insets in = getInsets(); Dimension d = getSize(); // translate origin to top of drawable area g.translate(in.left,in.right); // draw bounding rectangle g.drawRect(0,0,d.width-1,d.height-1); // if loadfg pressed, display the image if ( fgloaded ) { g.drawImage(fgImage2,0,0,this); } // end if } // end of paint method public void update(Graphics g) { // only wipe canvas if absolutely necessary if ( clearfg ) { g.clearRect(0,0,imgWidth,imgHeight); clearfg = false; } // end if paint(g); } // end of update method } // end of class fgndCanvas public class keyedCanvas extends Canvas { public void paint(Graphics g) { Insets in = getInsets(); Dimension d = getSize(); // translate origin to top of drawable area g.translate(in.left,in.right); // draw bounding rectangle g.drawRect(0,0,d.width-1,d.height-1); // if foreground just loaded, display it if ( justloadedfg ) { g.drawImage(fgImage2,0,0,this); } // end if // if the image has been chroma-keyed, display it if ( keyed ) { g.drawImage(keyedImage,0,0,this); } // end if } // end of paint method public void update(Graphics g) { // only wipe canvas if absolutely necessary if ( clearkeyed ) { g.clearRect(0,0,imgWidth,imgHeight); clearkeyed = false; } // end if paint(g); } // end of update method } // end of class keyedCanvas public class bkgndCanvas extends Canvas { public void paint(Graphics g) { Insets in = getInsets(); Dimension d = getSize(); // translate origin to top of drawable area g.translate(in.left,in.right); // draw bounding rectangle g.drawRect(0,0,d.width-1,d.height-1); // if loadfg pressed, display the image if ( bgloaded ) { g.drawImage(bgImage2,0,0,this); } // end if } // end of paint method public void update(Graphics g) { // only wipe canvas if absolutely necessary if ( clearbg ) { g.clearRect(0,0,imgWidth,imgHeight); clearbg = false; // all panels now clear } // end if paint(g); } // end of update method } // end of class bkgndCanvas // ############## // PROCESS EVENTS // ############## // update variables and scrollbars when values entered in text fields // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ // get values from hue selection text field & update values public class chromaTFAListener implements ActionListener { public void actionPerformed(ActionEvent e) { // parse integer try { int parsed1 = Integer.parseInt(chromaVal.getText()); // ensure values are valid (0<=parsed1<=360) if ( parsed1 >= 0 && parsed1 <= 360 ) { chroma = parsed1; // update variable chromaHue.setValue(parsed1); // update scrollbar } else { throw new NumberFormatException(); // invalid range } // end if } catch (NumberFormatException ex) { chromaVal.setText(String.valueOf(chroma)); // reset text field } // end of try/catch block } // end of actionPerformed } // end of class chromaTFAListener // get values from +/- deviation text field & update values public class rangeTFAListener implements ActionListener { public void actionPerformed(ActionEvent e) { // parse integer try { int parsed2 = Integer.parseInt(rangeVal.getText()); // ensure values are valid (0<=parsed2<=180) if ( parsed2 >= 0 && parsed2 <= 180 ) { deviation = parsed2; // update variable hueRange.setValue(parsed2); // update scrollbar } else { throw new NumberFormatException(); // invalid range } // end if } catch (NumberFormatException ex) { rangeVal.setText(String.valueOf(deviation)); // reset text field } // end of try/catch block } // end of actionPerformed } // end of class rangeTFAListener // update variables as scrollbars are adjusted // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ // get values from hue selection scrollbar & update variables public class chromaADJListener implements AdjustmentListener { public void adjustmentValueChanged(AdjustmentEvent e) { int val=(chromaHue.getValue()); // obtain value from scrollbar chroma = val; // update stored value chromaVal.setText(String.valueOf(val)); // update text field } // end of adjustmentValueChanged } // end of class chromaADJListener // get values from +/- deviation scrollbar & update variables public class rangeADJListener implements AdjustmentListener { public void adjustmentValueChanged(AdjustmentEvent e) { int val=(hueRange.getValue()); // obtain value from scrollbar deviation = val; // update stored value rangeVal.setText(String.valueOf(val)); // update text field } // end of adjustmentValueChanged } // end of class rangeADJListener // respond to button presses // ~~~~~~~~~~~~~~~~~~~~~~~~~ // load foreground image public class loadfgBAListener implements ActionListener { public void actionPerformed(ActionEvent e) { try { // grab pixels and refresh display fgPg.grabPixels(); } catch (InterruptedException ex) { System.err.println("Pixel Grab Interrupted!!"); ex.printStackTrace(); } // end of try/catch block fgImage2 = createImage(new MemoryImageSource(imgWidth,imgHeight,fgPixels,0,imgWidth)); fgloaded = true; // flag image as loaded justloadedfg = true; // flag keyed panel for update keyed = false; // discard old keyed image, use new fgImage fgCanvas.repaint(); // update display keyedCanvas.repaint(); } // end of actionPerformed } // end of class loadfgBAListener // return to original state public class clearBAListener implements ActionListener { public void actionPerformed(ActionEvent e) { fgloaded = false; // flag image as unloaded bgloaded = false; keyed = false; justloadedfg = false; clearfg = true; // flag image as cleared clearkeyed = true; clearbg = true; fgCanvas.repaint(); // update display keyedCanvas.repaint(); bgCanvas.repaint(); } // end of actionPerformed } // end of class clearBAListener // perform chroma-keying operation public class keyBAListener implements ActionListener { public void actionPerformed(ActionEvent e) { if ( fgloaded && bgloaded ) { // only key if images are loaded // loop-invariant expressions to determine the minimum/maximum hue int maxHue = chroma + deviation; int minHue = chroma - deviation; // chroma-key the image for (int y = 0; y < imgHeight; y++ ) { for (int x = 0; x < imgWidth; x++ ) { int index = y*imgHeight+x; // calculate index position (1D array) int currentHue=getH(fgPixels[index]); // get hue of current pixel // if hue of fgPixel in specified range, replace with bgPixel // consider case where hue - deviation < 0 if (deviation > chroma) { if (currentHue <= maxHue || currentHue >= (minHue + 360)) { keyedPixels[index] = bgPixels[index]; } else { keyedPixels[index] = fgPixels[index]; } // end if } else { // consider case where hue + deviation > 360 if (maxHue > 360) { if (currentHue <= (maxHue - 360) || currentHue >= minHue) { keyedPixels[index] = bgPixels[index]; } else { keyedPixels[index] = fgPixels[index]; } // end if } else { // standard case if (currentHue >= minHue && currentHue <= maxHue) { keyedPixels[index] = bgPixels[index]; } else { keyedPixels[index] = fgPixels[index]; } // end if } // end if } // end if } // end for } // end for keyedImage = createImage(new MemoryImageSource(imgWidth,imgHeight,keyedPixels,0,imgWidth)); justloadedfg = false; // We no longer want to display fgImage, keyed = true; // but the new keyed image instead. keyedCanvas.repaint(); // update display } // end if } // end of actionPerformed } // end of class keyBAListener // load background image public class loadbgBAListener implements ActionListener { public void actionPerformed(ActionEvent e) { try { // grab pixels and refresh display bgPg.grabPixels(); } catch (InterruptedException ex) { System.err.println("Pixel Grab Interrupted!!"); ex.printStackTrace(); } // end of try/catch block bgImage2 = createImage(new MemoryImageSource(imgWidth,imgHeight,bgPixels,0,imgWidth)); bgloaded = true; // flag image as loaded bgCanvas.repaint(); // update display } // end of actionPerformed } // end of class loadbgBAListener } // end of class mainPanel } // end of class ajt97c